Clamping device and method for detachably fixing a workpiece in position, and machine comprising such a clamping device

Abstract

The invention relates to a clamping device (1) and a method for detachably fixing a workpiece (3) having a free-form surface (2) in position. The clamping device (1) comprises an adapter apparatus (4), on the clamping body (5) of which an adapter clamping unit (6) is arranged which can be adjusted between an adapter release position and a stably locked adapter clamping position, in which the workpiece (3) can be form-fittingly held on the clamping body (5) by means of the adapter clamping unit (6). The clamping device (1) also comprises a shuttle body (9), in the clamping body receptacle (10) of which the clamping body (5) is inserted or can be inserted. A shuttle clamping unit (11) of the shuttle body (9) can be adjusted between a shuttle release position, in which the clamping body (5) can be inserted into the clamping body receptacle (10) and can be moved therein, and a stably locked shuttle clamping position, in which the clamping body (5) and the shuttle body (9) are fixed in position relative to one another.

Description

[0001] Clamping device and method for releasable positional fixing of a workpiece, as well as a machine with such a clamping device

[0002] The invention relates to a clamping device for the non-destructive, releasable positional fixation of a workpiece having a freeform surface, wherein the workpiece is in particular a blade element for a turbomachine, for example, a guide vane or impeller blade of a compressor or a turbine. The invention further relates to a method for the releasable positional fixation of the workpiece having the freeform surface, wherein the workpiece is fixed by means of the clamping device. The invention also relates to a machine that includes the clamping device and is configured to perform a machining operation on the workpiece.

[0003] It is necessary to securely fix such a workpiece in position, for example, for machining, measuring, etc. However, due to the workpiece's external shape, which features one or more freeform surfaces, this is currently quite complex. For example, it is known from the prior art to fix the workpiece in position using an adhesive bond. For instance, the workpiece is glued to a conventional adapter, which is then glued to a shuttle. Adhesive bonds were chosen to allow for the most versatile use of the adapter and shuttle – that is, for workpieces of different geometries. However, creating the adhesive bonds requires the use of adhesive, and to separate the workpiece from the shuttle or adapter, the adhesive bond must be dissolved, for which solvents are used, for example.Furthermore, cleaning the workpiece, adapter, and shuttle with a cleaning agent is necessary. It is evident that setting up for positional fixation and release of the workpiece takes a particularly long time. Moreover, the use of solvents and cleaning agents is environmentally unfriendly.

[0004] A device for fixing a workpiece to be machined using a machine tool is proposed by EP 2849907 Bl. As long as a clamping lever of the device is pressed down by a worker, the workpiece is firmly clamped or fixed in its position between a clamping jaw and a stop surface and / or a base plate for a machining operation with the machine tool.

[0005] US Patent 8061,699 B2 discloses a clamping system for aerofoils and vanes, wherein the clamping system comprises a complex arrangement of screw elements, spring-ball units, support elements, and rockers for clamping the aerofoils. The aerofoils are almost completely enclosed by a clamping unit of the clamping system and fixed by the aforementioned arrangement, such that one plate of the vane protrudes from the clamping system. Simple machining of the aerofoils is therefore prevented as long as the vane is clamped in the system. Furthermore, it is particularly time-consuming to have to tighten at least two screw connections to clamp the vane.

[0006] A similar issue arises with US 4805 351 A, which proposes a method for positioning turbine blades: Two screw operations are required to clamp the turbine blade in a holding device. Furthermore, the holding device is not very versatile, as it is designed for a single turbine blade outer geometry; turbine blades that differ even slightly in size and / or geometry cannot be fixed using the conventional holding device.

[0007] The object of the present invention is to reliably and with minimal effort fix a workpiece having a freeform surface in a releasable manner. This object is achieved by the subject matter of the independent claims. Advantageous embodiments of the invention are the subject matter of the dependent claims.

[0008] According to the invention, a clamping device and a method are proposed – each for the non-destructively releasable positional fixing of a workpiece having one or two or more freeform surfaces. Furthermore, a machine is proposed which includes the clamping device for fixing the workpiece and a working device for performing a work operation on the workpiece.

[0009] Each adapter assembly of the clamping device has a clamping body on which an adapter clamping unit is arranged. This unit is adjustable between an adapter release position and a securely locked adapter clamping position. The clamping body is, in particular, integrally manufactured with the adapter assembly or rigidly and / or immovably connected to it. When the adapter clamping unit is in the adapter release position, the workpiece can be inserted into the adapter clamping unit. The adapter clamping unit is then moved into the adapter clamping position, in which the workpiece is positively locked to the clamping body by means of the adapter clamping unit.The adapter device can (optionally) be designed so that the adapter clamping unit can only be adjusted into the adapter clamping position and / or locked in this position when the workpiece and the adapter device are positioned relative to each other, i.e., only when the workpiece is inserted into the adapter device.

[0010] The clamping device further comprises a shuttle body manufactured separately from the adapter assembly. This shuttle body includes a clamping body receptacle corresponding to the clamping body and a shuttle clamping unit, wherein the clamping body is inserted or can be inserted into the clamping body receptacle. The shuttle clamping unit is adjustable between a shuttle release position and a shuttle clamping position. In the shuttle release position, the clamping body can be inserted into the clamping body receptacle, if it has not already been inserted. Furthermore, in the shuttle release position, the clamping body inserted into the clamping body receptacle is guided in a translationally movable and tiltable manner within the clamping device in one plane. In contrast, the clamping body in the clamping body receptacle and the shuttle body are positionally fixed relative to each other in the stably locked shuttle clamping position.In the shuttle clamping position, the shuttle body and the adapter are positionally fixed to each other, i.e., connected. It is specifically designed that a purely force-fit or friction-fit connection is established between the clamping body receptacle and the clamping body in the shuttle clamping position. This is advantageous because it eliminates the need to align positive locking elements, allowing the clamping body and the clamping body receptacle to be connected in an infinite number of variations or positions. In contrast, a positive locking connection always requires the positive locking elements to be aligned into one of a finitely countable number of discrete positions. The clamping body receptacle is designed, for example, as a slot, a gap, or a groove, in which the clamping body is mounted or can be mounted in a plane so that it is translationally movable and tiltable in the shuttle release position.One or both of the clamping units have a clamping mechanism by means of which the respective clamping unit can be adjusted and / or locked in its corresponding clamping position. In other words, the adapter clamping unit has an adapter clamping mechanism by means of which the adapter clamping unit can be locked in the adapter clamping position, and additionally or alternatively, the shuttle clamping unit has a shuttle clamping mechanism by means of which the shuttle clamping unit can be locked in the shuttle clamping position. The shuttle clamping mechanism and / or the adapter clamping mechanism can also be designed as a quick-release clamping mechanism. A quick-release clamping mechanism is understood to be a clamping mechanism that differs from a conventional clamping mechanism at least in that adjusting and locking the quick-release clamping mechanism requires significantly less effort compared to a conventional clamping mechanism.This includes the fact that no tools are required to lock or release the quick-release mechanism; a human user can lock or release it by hand. Furthermore, a quick-release mechanism can be adjusted between its clamping and release positions more quickly than a conventional clamping mechanism. Typically, a quick-release mechanism does not have a thread or drive mechanism that would be needed to lock or release it.

[0011] The workpiece with the freeform surface(s) is, in particular, a blade element for a turbomachine, such as a guide vane or impeller blade of a compressor or turbine. Using the clamping device, this workpiece can be clamped particularly easily and with minimal effort, for example, to clamp it in a machine tool for further processing. Neither adhesive nor cleaning agents are required, as the workpiece is not glued to anything. Furthermore, clamping or fixing the workpiece is comparatively quick, as only the two clamping mechanisms need to be adjusted to their respective locking positions; there is no activation or curing time required for an adhesive bond. It is also advantageous that the clamping device allows the workpiece, especially the blade element, to be clamped or fixed in such a way that...It can be fixed in such a way that a radially outer end and a radially inner end of the blade element remain free and easily accessible for further work. This is particularly advantageous for easily and efficiently carrying out work on the tip and / or the base of the blade element – ​​especially on the mounting shaft of a turbine or compressor blade.

[0012] Furthermore, the clamping device is particularly flexible and versatile, as it can be adapted to different workpiece geometries. This means that workpieces with different freeform surfaces and geometries or shapes can be easily and repeatedly fixed in position relative to the shuttle body using the clamping device, without the need for any retooling. In other words, the same adapter can be used to fix different workpieces. For clamping workpieces with a geometric design where suitable locking is not guaranteed by the existing clamping elements and thus within the clamping device, one or more adapted clamping elements can be used, depending on the design. These are adapted to the shape of the respective workpieces and enable suitable locking of this workpiece geometry(ies).

[0013] In the process for the releasable positional fixing of the workpiece or the blade element having the freeform surface(s) using the clamping device, the workpiece and the shuttle body are positioned relative to each other in a first process step. For this purpose, a datum system of the workpiece is used, wherein the datum system has, in particular, six predefined points on the workpiece. By aligning these predefined points with respect to the shuttle body, the workpiece is aligned or positioned relative to the shuttle body as desired. The positions of the workpiece and the shuttle body are maintained unchanged for the subsequent steps of the process at least until both the workpiece and the adapter device, as well as the adapter device and the shuttle body, are fixed to each other.In a further step of the process, the adapter clamping unit is moved towards the workpiece, particularly by moving the adapter device while maintaining the position of the workpiece and the shuttle body. For this purpose, the clamping body of the adapter device – if not already done – is inserted into the corresponding clamping body receptacle, in which it can be moved translationally and / or tilting in one plane due to the guidance provided by the clamping body receptacle.

[0014] In a further step of the process, the adapter clamping unit of the adapter device is adjusted into its clamping position using the adapter clamping mechanism, while maintaining the position of the workpiece. This fixes the workpiece and the adapter devices to each other. Subsequently, in the next step, the shuttle clamping unit is adjusted into its clamping position using the respective shuttle clamping mechanisms, while maintaining the positions of the workpiece and the shuttle body. As a result, the workpiece and the shuttle body are fixed to each other by the adapter device.

[0015] The process is notably free of both the application of adhesive and the driving of a threaded element to fix the workpiece relative to the shuttle body. To remove the workpiece from the shuttle body, this is simply done by adjusting the adapter clamping unit to the adapter release position using the adapter clamping mechanism. By simply adjusting the shuttle clamping unit to its release position, the shuttle body and the clamping body can be separated, allowing the adapter clamping unit to be moved to a different workpiece.

[0016] Since no adhesive bond is required to fix the workpiece, all requirements associated with adhesive bonding are advantageously eliminated, in particular the storage, maintenance, and consumption of adhesives, cleaning agents and / or solvents, blasting media, etc., as well as the maintenance, operation, and servicing of devices for applying adhesive (e.g., mixing devices, etc.), for activating the adhesive (e.g., activation light units, heaters, etc.), and for removing the cured adhesive (e.g., cleaning equipment). Clamping or fixing the workpiece without adhesive is also significantly less energy-intensive than repeatedly creating an adhesive bond. This results in a particularly energy-efficient and low-cost method for the releasable, positional fixing of workpieces with freeform surfaces.Moreover, the clamping device, i.e., the clamping assembly, advantageously exerts neither excessive force nor excessive moment on the clamped workpiece. Consequently, the workpiece is securely and stably fixed in position, but deformation of the workpiece due to the clamping does not occur.

[0017] In other applications of the proposed clamping device, particularly when combined with the possibility of performing axis correction by the machine, the use of a workpiece datum system can be omitted. For example, the workpiece to be machined can be pre-positioned with sufficient accuracy in the clamping device using suitable contact surfaces, which are provided in particular on at least one clamping body and / or the adapter device and / or the shuttle body of the clamping device, so that it can be machined after the clamping units have been locked and, in particular, after axis correction by the machine.

[0018] The machine comprising the clamping device and the working device is, for example, a machine tool and / or measuring machine. In other words, the working device—as provided for in one possible embodiment of the machine—has a tool for machining the workpiece or the blade element, in particular a grinding tool, a milling tool, a polishing tool, etc. Alternatively or additionally, according to another possible embodiment, the working device has a coordinate measuring unit for capturing external coordinates of the workpiece. In any case, the clamping device can be attached to the machine in such a way that the workpiece is positionally fixed for the machining operation, i.e., for example, machining and / or measuring, in relation to the working device, in particular to a machining or measuring coordinate system of the machine or the working device.The shuttle body essentially acts as a workpiece carrier for the machine and can, for example (optionally), only be inserted into the machine in discrete, predefined positions. This ensures that the coordinate system of the machine or the work fixture and the shuttle body are always arranged in a known positioning relationship to each other as soon as the shuttle body is properly inserted or installed in the machine. Consequently, a known positioning relationship also exists between the datum system of the workpiece (i.e., its six predefined points) and the coordinate system of the machine / work fixture as soon as the shuttle body, along with the adapter and the workpiece fixed to it, is properly inserted into the machine. Since the time required to fix the workpiece using the proposed clamping device is particularly short, unfavorable downtime or other factors are minimized.Downtime of downstream process equipment - in particular the machine tool and / or measuring machine - is advantageously particularly short.

[0019] According to one possible embodiment of the clamping device, the clamping function of the adapter clamping mechanism and / or the shuttle clamping mechanism is achieved by means of a force-fit, a positive-fit, and / or a friction-fit. In practice, the clamping function usually exhibits at least two of these locking mechanisms. The clamping function can thus be implemented by means of force redirection and / or force transmission devices of various designs, which, for example, include at least one wedge drive. In particular, the clamping function of the adapter clamping mechanism and / or the shuttle clamping mechanism is designed to enable efficient and reliable clamping of the workpiece in a predetermined position, even under the load of a machining operation.

[0020] According to one possible embodiment of the clamping device, the adapter clamping mechanism and / or the shuttle clamping mechanism are designed to have a toggle lever mechanism, whereby the corresponding toggle lever mechanism can be adjusted into a stable locking position by moving it beyond its dead center. A toggle lever mechanism is a particularly simple clamping mechanism in terms of design and ease of use, and can therefore be a quick-release clamping mechanism. This makes locking the adapter clamping mechanism or the shuttle clamping mechanism particularly easy.

[0021] According to one possible design of the clamping device, the adapter clamping mechanism and / or the shuttle clamping mechanism are designed to incorporate a wedge, a screw connection, or a spring mechanism. Depending on the structure and / or geometry of the workpiece and the shuttle, various clamping designs can be used. Since the clamping device operates in a wear-promoting environment (particles from grinding wheels, chips, etc.), wedges, screw connections with their threaded components, or spring mechanisms can be easily and cost-effectively replaced as needed, thus reducing maintenance costs. The respective clamping mechanisms are designed in such a way that the forces and moments required for clamping are decoupled from the workpiece and do not act directly on it, in order to prevent workpiece deformation or the occurrence of stresses within the workpiece.One or more spring devices, and in particular elastic intermediate elements, can be used, for example, as compensation element(s), especially for tolerance compensation, in the case of angular deviations and / or in connection with geometric adjustments, for example in the case of clamping in connection with freeform surfaces.

[0022] In another possible embodiment, the shuttle body has as many clamping body receptacles as adapter devices, wherein the clamping bodies of the adapter devices can be inserted into and moved independently of one another within the clamping body receptacles. This allows the workpiece to be fixed or connected to the shuttle body at two or more points, thereby holding the workpiece in position particularly securely and stably relative to the shuttle body.

[0023] According to a possible further development, the contact areas of the adapter clamping unit facing the workpiece are convex, i.e., round or cylindrical, so that—when the workpiece is fixed to the adapter device—it only touches the adapter clamping unit at a single point or along a line (namely, with a convex portion extending toward the workpiece). Conversely, this further development stipulates that the workpiece held in / on the adapter device by means of the adapter clamping unit and the adapter clamping unit do not make full contact with each other. This ensures, firstly, that the (respective) adapter clamping unit can be reliably positioned and clamped to the workpiece, even if the workpiece and the corresponding adapter clamping unit are positioned at an angle to each other. Furthermore, the clamping device, due to the merely point-like or...Due to the linear contact, only a particularly small portion of the workpiece is covered, so that for a subsequent machining operation, a particularly large portion of the workpiece is exposed or accessible to the work device, or rather, only a comparatively small portion of the workpiece surface is covered by the clamping device. The clamping device is particularly easy to operate, since the respective clamping body receptacle is designed such that, in the shuttle release position, it only allows translational movement and tilting of the clamping body in one plane of the clamping device. According to one embodiment, it is optionally provided that all other degrees of freedom of the clamping body are locked in the shuttle release position, so that only translational movement and tilting of the clamping body, especially around the workpiece, are possible.This allows the clamping element to be guided in the clamping element receptacle and, for example, to be moved slidably within it.

[0024] Further characteristics will emerge from the following description in connection with the figures. It shows

[0025] Fig. 1 shows a schematic representation of an exemplary adapter device of a clamping device viewed along a transverse axis Y, wherein a workpiece having a freeform surface is releasably fixed in position by means of the adapter device;

[0026] Fig. 2 shows a schematic representation of the exemplary adapter device with a view along a vertical axis Z;

[0027] Fig. 3 shows a schematic representation of the exemplary clamping device;

[0028] Fig. 4 shows a schematic representation of another exemplary embodiment of the clamping device;

[0029] Fig. 5 shows a schematic representation of another exemplary embodiment of the clamping device;

[0030] Fig. 6 shows a schematic representation of another exemplary embodiment of the

[0031] Clamping device; Fig. 7 a schematic representation of another exemplary embodiment of the clamping device;

[0032] Fig. 8 shows a schematic representation of another exemplary embodiment of the adapter device;

[0033] Fig. 9 shows a schematic representation of another exemplary embodiment of the adapter device;

[0034] Fig. 10 shows a schematic representation of another exemplary embodiment of the adapter device;

[0035] Fig. 11 shows a schematic representation of another exemplary embodiment of the adapter device;

[0036] Fig. 12 shows a schematic representation of another exemplary embodiment of the adapter device;

[0037] Fig. 13 shows a schematic representation of another exemplary embodiment of the adapter device; and

[0038] Fig. 14 shows a flowchart to illustrate a method for the releasable positional fixing of a workpiece having a freeform surface.

[0039] In the following, a clamping device 1 and a method - each for the releasable positional fixing of a workpiece 3 having a freeform surface 2 or two or more freeform surfaces 2 - as well as a machine comprising the clamping device 1 (not shown) are described together.

[0040] Figure 1 shows a schematic representation of an adapter device 4 of the clamping device 1, viewed along a transverse axis Y. The workpiece 3, which has the freeform surface 2 or freeform surfaces 2, is releasably fixed in position by means of the adapter device 4. In this example, the workpiece 3 is a blade element for a turbomachine, which is to be clamped for a further machining operation, namely in the machine, which is a machine tool and / or measuring machine that will be explained in more detail below.

[0041] The adapter assembly 4 of the clamping device 1 has a clamping body 5 on which an adapter clamping unit 6 is arranged. This unit is adjustable between an adapter release position (not shown) and a securely locked adapter clamping position (see Fig. 1). In the adapter release position, the workpiece 3 can be inserted into the adapter clamping unit 6. In the adapter clamping position, the workpiece 3 is positively locked to the clamping body 5 by means of the adapter clamping unit 6. The adapter assembly 4 is designed such that the adapter clamping unit 6 can only be locked in the adapter clamping position when the workpiece 3 and the adapter assembly 4 are positioned relative to each other, i.e., when the workpiece 3 is inserted into the adapter assembly 4. The adapter clamping unit 6 has an adapter clamping mechanism 7 by means of which the adapter clamping unit 6 can be locked in the adapter clamping position.According to the present example, the adapter clamping mechanism 7 has a first toggle lever 8 which can be adjusted into a stable locking position by moving it beyond its dead center. In the stable locking position of the first toggle lever 8, the adapter clamping unit 6 is arranged in its adapter clamping position and secured in this position in a way that allows for non-destructive re-release.

[0042] Fig. 2 shows a schematic representation of the adapter device 4 viewed along a vertical axis z. In the present example, contact areas 12 of the adapter clamping unit 6 are convex, i.e., round or cylindrical, so that the contact area on the adapter device 4 (see Fig. 2) is convex.

[0043] 1) The fixed workpiece 3 and the adapter clamping unit 6, or rather their contact areas 12, only touch each other at points or, at most, along lines. The workpiece 3, held in / on the adapter device 4 by means of the adapter clamping unit 6, and the adapter clamping unit 6 do not touch each other over a surface. This allows the adapter clamping unit 6 to be reliably positioned and clamped against the workpiece 3, even if the workpiece 3 or a section thereof and the corresponding adapter clamping unit 6 are arranged at an angle to each other. This is illustrated in Fig. 2 by further possible workpiece positions 3a, 3b, shown with dashed lines. A schematic representation of the clamping device 1 is shown in Fig. 3, where it can be seen that the clamping device 1 also has a shuttle body 9, which is manufactured separately from the adapter device 4.The shuttle body 9 comprises a clamping body receptacle 10 corresponding to the clamping body 5 and a shuttle clamping unit 11, wherein the clamping body 5 is inserted into or can be inserted into the clamping body receptacle 10. The shuttle clamping unit 11 is adjustable between a shuttle release position and a shuttle clamping position. In the shuttle release position, the clamping body 5 can be inserted into the clamping body receptacle 10 and is movable within it. In contrast, the clamping body 5 and the shuttle body 9 are positionally fixed to one another in the stably locked shuttle clamping position. In the shuttle clamping position, the shuttle body 9 and the adapter device 4 are therefore positionally fixed to one another, i.e., connected to each other. The shuttle clamping unit 11 has a shuttle clamping mechanism 13 by means of which the shuttle clamping unit 11 can be locked in the shuttle clamping position.According to the present example, the shuttle clamping mechanism 13 has a second toggle lever 14, which can be adjusted into a stable locking position by moving it beyond its dead center. In the stable locking position of the second toggle lever 14, the shuttle clamping unit 11 is arranged in its shuttle clamping position and secured in this position in a way that allows for non-destructive re-release.

[0044] Furthermore, as can be seen from Fig. 3, the respective clamping element receptacle 10 is designed such that, in the shuttle release position, translational movement and tilting of the clamping element 5 in one plane (here in the X or YZ plane) of the clamping device 1 are permitted, whereas all other degrees of freedom of the clamping element 5 are locked in the shuttle release position. It can also be seen that the clamping element receptacle 10 is designed as a slot or the like, in the plane of which the clamping element 5 is arranged, or can be arranged, to be translationally movable and tiltable in the shuttle release position.

[0045] Fig. 4 shows a possible further development of the clamping device 1, which has two or more adapter devices 4. The shuttle body 9 accordingly has as many clamping element receptacles 10 as adapter devices 4, wherein the clamping elements 5 of the adapter devices 4 can be inserted into the clamping element receptacles 10 independently of one another and are movable within them. In this way, the workpiece 3 can be fixed at two or more points or connected to the shuttle body 9.

[0046] Figures 3 and 4 further show that the shuttle clamping unit 11 in this example has a force deflection and transmission device 15 – here implemented only as an example, a wedge drive. This allows a force exerted by the shuttle clamping mechanism 13 to be easily and efficiently transferred to the clamping body 5 and, if necessary (depending on the angular relationships of the wedge drive), translated. It is possible for part of the force deflection and transmission device 15 or the wedge drive and the shuttle body 9 to be formed integrally.

[0047] Fig. 5 shows a schematic representation of another exemplary embodiment of the clamping device 1, whose force redirection and transmission device 15 is also implemented as a wedge drive in this example. The shuttle clamping mechanism 13 is actuated by means of a clamping screw 16. The force exerted via this screw is directed to the clamping body 5 to fix it in place.

[0048] In conjunction with the clamping body 9, the clamping screw 16, for example, drives a wedge of the force deflection and transmission device 15, which generates a clamping force that locks the adapter device 4. The clamping screw torque acts on the clamping body 5 of the adapter device 4 and does not directly act on the workpiece 3. In case of wear due to an abrasive environment, the clamping screw 16 and the part of the shuttle body 9 in which the clamping screw 16 is threaded can be replaced, especially since no particular precision is required in this area of ​​the shuttle body 9.

[0049] Fig. 6 shows a schematic representation of a further exemplary embodiment of the clamping device 1 shown in Figures 4 and 5, which has several adapter devices 4. In the illustrated embodiment, the clamping body receptacles 10 or their clamping body guide planes X, ZY in the shuttle body 9 are not arranged parallel to each other, but inclined (the coordinate system of the respective guide plane of the clamping body receptacle is thus arranged at a corresponding inclination). Depending on the shape of the workpiece 3 to be clamped, such an embodiment enables improved, in particular geometrically adapted, clamping of the workpiece in the clamping device 1, whereby the proposed embodiment also allows for greater rigidity of the clamping device.

[0050] Fig. 7 shows a schematic representation of another exemplary embodiment of the clamping device 1. This clamping device 1 has a multi-part adapter assembly 4, which in this example has two clamping bodies 5 that are received in clamping body receptacles 10 of the clamping device 1. Furthermore, the adapter assembly 4 has several adapter clamping units 6. Two of the exemplary adapter clamping units 6 are each received on the adapter assembly 4 by means of spring devices 76 in the form of leaf springs. On the side of the shuttle body 9 opposite the clamping body receptacles 10 of the clamping device 1, an exchange system 80 is arranged, which enables quick and precise connection of the clamping device 1 to the machine tool.

[0051] As can be seen in connection with this illustration, the adapter devices can alternatively be made significantly wider or thicker, and thus stiffer or more stable, instead of several thin sheets. This is independent of any clamping within the shuttle body 9. By using thicker or stiffer adapter devices 4, for example, the number of required adapter devices 4 can be reduced. To enable clamping compensation in the clamping body receptacles 10, which is necessary due to different thicknesses of clamping bodies 5, compensating elements 79 of different thicknesses, or, in an embodiment according to Fig. 6, with differently inclined surfaces such as wedges 78, can be inserted into the clamping body receptacles. Elastic elements can also be used as compensating elements 79 to compensate for possible thickness or angle deviations.

[0052] Fig. 8 shows a schematic representation of another exemplary embodiment of the adapter device 4 and its adapter clamping mechanism 7, the function of which is described by the procedure for positioning the workpiece 3 in the clamping device 1 using a datum system. First, the workpiece is positioned relative to the shuttle body 9 using the datum system, which defines the positions of, in particular, six position points (6-point nest). The adapter device 4, guided in the clamping body receptacle 5, is aligned with the workpiece 3 with the adapter clamping mechanism 7 open, and the adapter clamping mechanism 7 is closed by pivoting the clamping lever 74, thus clamping it against the workpiece, which remains in the correct position on the 6-point nest. The screw 71 clamps one side of the adapter clamping mechanism 7 to the workpiece. Subsequently, a second screw 71 is adjusted to clamp the other side of the workpiece 3.The adapter device 4 is thus firmly and correctly connected to the workpiece 3. The protective bracket 73 protects the workpiece 3 from damage by the screw 71. Subsequently, the adapter device 4 is firmly connected to the shuttle body 9 via the clamping body 5 using the shuttle clamping unit 7, thereby fixing the workpiece 3 and the shuttle body 9 to each other in position by means of the adapter device 4.

[0053] Fig. 9 shows a schematic representation of another exemplary embodiment of the adapter device 4 and its adapter clamping mechanism 7. Its function is also described using the procedure for positioning the workpiece 3 in the clamping device 1 by means of a datum system. First, the workpiece is positioned on the datum system, which defines the positions of, in particular, six position points (6-point nest), relative to the shuttle body 9. Then, the adapter device 4 with the clamping lever 74 open is aligned with the workpiece 3. The clamping lever 74 is driven by means of the screw 71 and rotated about its axis of rotation, thereby clamping the workpiece and thus firmly connecting it to the adapter device 4. Subsequently, the other screw 71 is adjusted so that the other side of the workpiece is clamped individually. The adapter device 4 is thus firmly and correctly connected to the workpiece 3.Subsequently, the adapter device 4 is firmly connected to the shuttle body on the clamping body 5 by means of the shuttle clamping unit, whereby the workpiece 3 and the shuttle body 9 are fixed to each other in position by means of the adapter device 4.

[0054] Fig. 10 shows a schematic representation of another exemplary embodiment of the adapter device 4 and its adapter clamping mechanism 7. In this embodiment, the workpiece 3 is clamped to the adapter device 4 against a stop 75 formed thereon. In this example, a clamping force is applied to one longitudinal edge of the workpiece 3. The stop 75 on the opposite longitudinal edge prevents the workpiece 3 from slipping. This stop 75 can also be designed such that additional machining forces in different directions can be absorbed during subsequent machining of the workpiece 3.

[0055] Figures 11 and 12 show schematic representations of further exemplary embodiments of the adapter device 4. The adapter devices 4 in the preceding figures show embodiments in which, when clamping workpieces 3 in the form of blade elements or blades, these are clamped between the inlet and outlet edges. Alternatively, a blade can also be clamped between the suction and pressure sides. This reduces the risk of deformation of the workpiece 3 and, depending on the design, allows the clamping forces to be significantly increased without increasing the probability of damage or deformation of the workpiece 3. Figures 11 and 12 schematically show such arrangements for adapter devices 4, which can be arranged, for example, at the base and head of such a blade element with a Z-profile.As can be seen in detail in the figures, the respective workpieces 3 are fixed to the respective adapter device 4 by means of an adapter clamping mechanism 6, which uses screws 71 to clamp the workpiece against contact areas 12 of the adapter device 4. In the embodiment of the adapter device 4 shown in Fig. 11, the adapter clamping mechanism 6 has a protective support 72 to protect the workpiece 3 from damage at the clamping position.

[0056] Fig. 13 shows a schematic representation of a further exemplary embodiment of the adapter device 4 and its adapter clamping mechanism 7, in particular a further embodiment for an adapter device 4 for use on the side of a Z-profile of a workpiece 3 in the form of a blade element. In this embodiment, the adapter clamping mechanism 7 has wide, slender clamping levers 74, which, for example, allow both the clamping of the blade element and the grinding of the Z-profile in the machine tool.

[0057] In the method for the releasable positional fixing of the workpiece 3 or the blade or blading element having the freeform surface(s) 2, as illustrated by means of a flowchart in Fig. 14, the clamping device 1 is used as follows: First, both clamping units 6, 11 are adjusted to their respective release positions, if this has not already been done. In a first process step S1, the workpiece 3 and the shuttle body 9 are then positioned relative to each other. For this purpose, a datum system of the workpiece 3 or the blading element can be used, whereby the datum system can, in particular, have six predefined points on the workpiece 3, according to which it is aligned or positioned as desired with respect to the shuttle body 9. In a further step S2 of the process, the adapter clamping unit 6 or 11 is adjusted to its respective release position.The adapter clamping units 6 are moved towards the workpiece 3, in particular by moving the adapter device(s) 4 while maintaining the positions of the workpiece 3 and the shuttle body 9. Beforehand, the clamping body(s) 5 of the adapter device(s) 4 are inserted into the clamping body receptacle(s) 10, if this has not already happened. If the clamping device 1 has two or more adapter devices 4, and consequently a corresponding number of shuttle clamping units 11, then, depending on the number of adapter devices 4 of the clamping device 1, two or more of the adapter clamping units 6 are moved translationally and / or tilting towards the workpiece 3 in a plane X, YZ of the clamping device 1, as described above, at least as many as are required to securely fix the workpiece 3.In a further step S3 of the procedure, the adapter clamping units 6 are then adjusted to their clamping position by means of the respective clamping mechanism 7 while maintaining the position of the workpiece 3, thereby fixing the workpiece 3 and the adapter devices 4 to each other in position.

[0058] In the subsequent step S4, while maintaining the positions of the workpiece 3, the adapter device(s) 4, and the shuttle body 9, the respective shuttle clamping unit 11 is adjusted to the respective shuttle clamping position by means of the associated shuttle clamping mechanism 13. As a result, the workpiece 3 and the shuttle body 9 are positionally fixed to one another by means of the adapter devices 4.

[0059] The process is free of both the application of an adhesive and the driving of a threaded element to fix the workpiece 3 in relation to the shuttle body 9. To remove or release the workpiece 3 from the shuttle body 9, the adapter clamping unit 6 is moved into the adapter release position by means of the adapter clamping mechanism 7. If the adapter clamping units 6 are to be moved to a different workpiece 3, the shuttle clamping unit 11 is moved into its shuttle release position, thereby separating the shuttle body 9 and the clamping body 5.

[0060] The machine, implemented here as a machine tool and / or measuring machine, has a work fixture comprising a tool for machining the workpiece 3 or the blade element, in particular a grinding tool, a milling tool, a polishing tool, etc., and a coordinate measuring unit for capturing the external coordinates of the workpiece 3. The clamping device 1 can be attached to the machine in such a way that the workpiece 3 is positionally fixed for the machining operation and / or measurement in relation to the work fixture, in particular to a machining or measuring coordinate system of the machine or the work fixture. The shuttle body 9 essentially acts as the workpiece carrier of the machine. It is specifically intended that the workpiece 3 is fixed externally to the shuttle body 9, particularly while a machining operation is being performed on another workpiece 3 using the machine.According to the example described here, the shuttle body 9 can only be inserted into the machine in discrete, predefined positions, so that the coordinate system of the machine or the work device and the shuttle body 9 are always arranged in a known positioning relationship to each other as soon as the shuttle body 9 is inserted or installed in the machine as intended. Consequently, when using a datum system of the workpiece 3 (that is, its six predefined points), a known positioning relationship also exists between it and the coordinate system of the machine / work device as soon as the shuttle body 9, together with the adapter device 4 and the workpiece 3 fixed to it, is inserted into the machine as intended.

[0061] The proposed clamping device 1, the proposed method, and the proposed machine each demonstrate a way to reliably and with minimal effort fix a workpiece with a freeform surface in a releasable manner. The core concept here is a force- and moment-free connection between the workpiece 3 and the shuttle body 9, deliberately avoiding the use of adhesives. This results in advantages due to savings in adhesives and auxiliary materials (mixing nozzles, blasting particles, etc.), reduced environmental impact (waste materials, fumes, etc.), and time savings (preparation and post-processing associated with bonding, as well as curing and cleaning times, etc.).A mechanically rigid counter bearing for absorbing forces / moments exerted on the workpiece 3 by means of the machine during a work operation and a fastening device for clamping the workpiece 3 are combined in a particularly advantageous and compact manner.

[0062] The proposed items represent an advantageous alternative to conventional adhesive shuttles, requiring no consumables such as adhesives, cleaning agents, etc. Furthermore, the invented items are fundamentally suitable for all similar clamping situations. [REFERENCE SIGN LIST]

[0063] 1 clamping device

[0064] 2 Freeform surface

[0065] 3 workpieces

[0066] 3 a Workpiece position

[0067] 3b Workpiece position

[0068] 4 Adapter setup

[0069] 5 clamping bodies

[0070] 6 adapter clamping unit

[0071] 7 Adapter clamping mechanism

[0072] 8 first toggle lever mechanism

[0073] 9 Shuttle bodies

[0074] 10 clamping body holder

[0075] 11 Shuttle clamping unit

[0076] 12 Contact area

[0077] 13 Shuttle clamping mechanism

[0078] 14 second toggle lever mechanism

[0079] 15 Force deflection and transmission device 16 Tensioning screw

[0080] 71 screw

[0081] 72 Protective measure

[0082] 73 crash bars

[0083] 74 clamping levers

[0084] 75 stop

[0085] 76 Spring assembly

[0086] 78 wedge

[0087] 79 Compensation element

[0088] 80 interchangeable system

[0089] 51st procedure step

[0090] 52nd process step

[0091] 53 Procedure step

[0092] XYZ plane

Claims

REQUIREMENTS 1. Clamping device (1) for releasably positioning a workpiece (3) having a freeform surface (2), wherein the clamping device (1) comprises: - an adapter device (4) with a clamping body (5) on which an adapter clamping unit (6) is arranged, which is adjustable between an adapter release position and a stably locked adapter clamping position in which the workpiece (3) can be positively locked to the clamping body (5) by means of the adapter clamping unit (6), - a shuttle body (9) which has a clamping body receptacle (10) corresponding to the clamping body (5) and at least one shuttle clamping unit (11), wherein the shuttle clamping unit (11) is adjustable between a shuttle release position in which the clamping body (5) can be inserted into the clamping body receptacle (10) and is guided therein in a plane (X, YZ) of the clamping device (1) so as to be translationally movable and tiltable, and a stably locked shuttle clamping position in which the clamping body (5) in the clamping body receptacle (10) and the shuttle body (9) are positionally fixed relative to each other, wherein the adapter clamping unit (6) has an adapter clamping mechanism (7) by means of which the adapter clamping unit (6) can be locked in the adapter clamping position, and / or the shuttle clamping unit (11) has a shuttle clamping mechanism (13) by means of which the shuttle clamping unit (11) can be locked in the shuttle clamping position.

2. Clamping device (1) according to claim 1, characterized in that the clamping function of the adapter clamping mechanism (7) and / or the shuttle clamping mechanism (13) is achieved by means of a force connection, and / or by means of a positive connection and / or by means of a friction connection.

3. Clamping device (1) according to one of the preceding claims, characterized in that the adapter clamping mechanism (7) and / or the shuttle clamping mechanism (13) has / has a toggle lever mechanism (8, 14), wherein the corresponding toggle lever mechanism (8, 14) can be adjusted into a stable locking position by adjusting it beyond its dead center.

4. Clamping device (1) according to one of the preceding claims, characterized in that the adapter clamping mechanism (7) and / or the shuttle clamping mechanism (13) has / has a wedge (78), a screw connection (71) and / or a spring device (76).

5. Clamping device (1) according to one of the preceding claims, characterized in that it has two or more adapter devices (4), and the shuttle body (9) has as many clamping body receptacles (10) as adapter devices (4), wherein the clamping bodies (5) of the adapter devices (4) can be inserted into the clamping body receptacles (10) independently of one another and can be moved within them.

6. Clamping device (1) according to one of the preceding claims, characterized in that contact areas (12) of the adapter clamping unit (6) arranged towards the workpiece (3) are convex, so that when the workpiece (3) is fixed to the adapter device (4), it only touches the adapter clamping unit (6) at points or in a line.

7. Clamping device (1) according to one of the preceding claims, characterized in that all degrees of freedom of the clamping body (5) deviating from a movement in the plane (X, YZ) of the clamping device (1) are locked in the clamping body receptacle (10) in the shuttle release position.

8. Method for releasably positioning a workpiece (3) having a freeform surface (2) by means of a clamping device (1) designed according to one of the preceding claims, wherein 51 the workpiece (3) and the shuttle body (9) are positioned relative to each other, 52 the adapter clamping unit (6) is moved towards the workpiece (3) in particular by moving the adapter device (4) while maintaining the position of the workpiece (3) and the position of the shuttle body (9), wherein the clamping body (5) of the adapter device (4) is movable translationally and / or tiltingly in the clamping body receptacle (10) of the shuttle body (9) in a plane (X, YZ) of the clamping device (1), 53 the adapter clamping unit (6) is adjusted into its clamping position by means of the adapter clamping mechanism (7) while maintaining the position of the workpiece (3), thereby fixing the workpiece (3) and the adapter device (4) positionally to each other, 54 the shuttle clamping unit (11) is adjusted to its clamping position by means of the shuttle clamping mechanism (13) while maintaining the position of the workpiece (3), the adapter device (4) and the position of the shuttle body (9), whereby the workpiece (3) and the shuttle body (9) are fixed positionally to each other by means of the adapter device (4).

9. Machine for performing a work operation on a workpiece (3) having a freeform surface (2), wherein the machine has the clamping device (1) designed according to one of claims 1 to 7 and a working device, and the clamping device (1) can be attached to the machine in such a way that the workpiece (3) is positionally fixed in relation to the working device for the work operation.

10. Machine according to claim 9, characterized in that the working device has a tool for machining the workpiece (3).

11. Machine according to claim 9 or 10, characterized in that the working device has a coordinate measuring unit for capturing external coordinates of the workpiece (3).

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